I feel like off-chain ZK applications are really undervaluing the potential of just using STARKs, including for privacy-demanding use cases.

These days a STARK is < 100 kB, for off-chain use cases that amount of  bandwidth is utterly trivial compared to the client-side prover time savings that come from using STARKs.

Absolutely agree! STARKs offer incredible efficiency, and their robustness for privacy-centric applications is unparalleled. It's surprising more projects haven't embraced them for off-chain solutions. The minimal bandwidth requirement combined with prover time savings makes a compelling case.